Drier



March 17, 1942. o. GANG 2,276,955

DRIER Filed Jan. 11, 1959 2 Sheets-Sheet 1 INVENTOR. 0114710! bazm,

Patented Mar. 17, 1942 DRIER Orville Gano, Burley, Idaho, assignor to Potato Corporation of Idaho, Garwood, N. J a corporation of Idaho Application January 11, 1939, Serial No. 250,258-

8 Claims.

The present invention relates to driers and embodies, more specifically, a mechanism by means of which material is dried by being carried through a drying chamber on conveying mechanism of an improved type.

It is common practice to provide drying chambers within which a plurality of conveyors are mounted in order that the material may be passed back and forth within the chamber during the drying operation. The present invention accepts this practice and provides an improved conveyor mechanism by means of which the number of conveyors necessary for a given number of passes through the drying chamber is reduced over those required in conventional drying practice.

In accordance with the present invention, it has been found that certain physical properties of certain substances to be dried can be utilized in connection with conveying apparatus to expedite the drying mechanism. For example, in the case of drying potatoes which have been riced or extruded, the cooked potato, upon being riced and delivered to the conveyor belt, can be caused to adhere to the belt in order that it will make two passes through the drying chamber, one while lying on top of the belt and the second pass while adhering to it on the under side of the belt in the return direction of motion thereof.

It is, accordingly, an object of the present invention to provide an improved form of drying mechanism by means of which material having certain properties may be passed through the drying chamber a given number of times with fewer conveyors than has heretofore been possible.

A further object of the invention is to provide a mechanism of the above character in which certain material may be dried whilebeing carried by a single conveyor in a plurality of directions.

A further object of the invention is to provide a mechanism by means of which the foregoing conveyor travel is accomplished without substantial injury to the product being dried.

A further object of the-invention is to provide an improved drying mechanism wherein the flow of the drying medium may becontrolled in an eiiective manner.

Further objects of the invention will be observed upon reading the following detailed description in connection with the accompanying drawings, wherein:

Figure 1 is a diagrammatic illustration of a invention.

Figure 4 is a view similar to Figure 1, showing a further modification of the invention.

With reference to the above drawings and particularly Figures 1 and 2, an elongated drying chamber'is illustrated at It and is provided with an inlet II to which air or other drying medium is supplied by means of a fan I Z. The air flows through heating coils I3 and on through the chamber ID to the exhaust pipe M which is positioned at the end of chamber l0 distant from the inlet ll.

Within the chamber 10 is provided an upper conveyor l5 which is supported by rollers l6 and I1, and a lower conveyor l8 that is supported upon rollers l9 and 20. In the illustration shown, the lower conveyor is mounted so that its lower stretch lies outside the chamber L. This obviously may be changed without departing from the invention, it being only necessary that the upper stretch of the lower conveyor lie within the chamber I0.

The material to be dried is supplied at 2| which diagrammatically illustrates an extruder or ricer for potatoes or other substances of similar character which are to be dried. In the embodiment of the invention actually in commercial operation, the device Was designed for and used in connection with the manufacture of dried cooked potato, and it is with this product that the invention is now concerned in commercial operation, although it is quite apparent that the machine may be adapted for use in connection with drying other products having similar characteristics, as :above noted.

In accordance with the present invention, it is essential that the upper conveyor l5 be formed of a material such as canvas having a low specific heat. When the riced potato is delivered to such a belt, it is carried through the drying chamber ID on the upper stretch of the belt as indicated by the top arrow in'Figure 1. This is the first pass through the drying chamber. As the conveyor passes around the roller I 6 to return, the potato product will follow the conveyor because it will adhere thereto by reason of the fact that the conveyor is of low specific heat and thus permits the adhesion. In order to support the lower stretch of the conveyor l5, idler rollers 22 are provided, these rollers being preferably formed of wide meshed wire as illustrated in Figure 2, in order that a minimum amount of crushing of the material on the under side of the belt may take place.

The material will thus be brought back to the end of the drying chamber l adjacent the exhaust outlet it where a brush, scraper or other suitable mechanism 23 is provided to remove the material from the lower span of the upper conveyor. The material then falls upon the upper span of the lower conveyor [8 and passesin the direction of the arrow in Figure l to a dicharge hopper 24. It has been found that excess moisture can be eliminated by providing a bank of steam pipes Or other suitable heating mechanism as illustrated at 25 in Figure 1. When the scraper or brush member 23 removes the product from the lower span of the upper belt, the product is in a semi-dry condition, the drying being completed during its travel on the lower conveyor I8 to the hopper 24.

In the construction shown in Figure 3-, the invention is embodied in a slightly different form of drying mechanism in order that the motion of the drying medium may be controlled more effectively. Inasmuch as the conveying mechanism is the same as that illustrated in Figure 1, further description thereof is unnecessary. The drying medium consists of air taken from the atmosphere through a duct 25 and supplied to a fan 21 by means of which the medium is passed through a heating chamber 28. ing chamber 28, the medium is supplied to the drying chamber by means of a duct 29, the duct supplying the medium between the upper and lower conveyors. The air is then removed from the lower portion of the drying chamber I6 by means of a fan 38 which passes the removed air through a secondary heating chamber 3! and returns it to the top of the drying chamber H1 above the upper conveyor l5. Bailles 32 and 33 are provided to control and restrict the path of flow of the medium in the manner above described and, after passing through the drying chamber in this fashion, the material is discharged through an exhaust duct 34 by means of a suction fan 35. From the suction fan 35 the drying .i

medium may be discharged to the atmosphere through ducts 36 and 3? and a by-pass 38 is provided by means of which the medium may be recirculated. Dampers 39 and 40 are provided to control the extent of such re-circulation and the extent of air taken from the atmosphere through the duct 26.

In the construction shown in Figure 4., the same conveying means is used as is provided in the modifications shown in Figures 1 and 3. manner of supplying heated air to the drying chamber IE! is also the same as illustrated in connection with Figure 1. In Figure 4, however, air is removed from the region of the drying chamber between the upper and lower belts and introduced into the top portion of the drying chamber. This is accomplished by means of an exhaust duct 4! which carries the air to a fan 42 from which the air is returned to the drying chamber 10' through a duct 43 and inlet 44.

By means of the foregoing structure in which conveyors formed of material having low specific heat are used, the material is carried through the drying chamber with a fewer number of conveyors than has heretofore been possible. The

From the heat- The invention is applicable, of course, only for use in connection with drying substances which are relatively sticky, such as cooked and riced potatoes, but it will be understood that the invention is not to be limited to uses involving only the drying of cooked riced potato. It will also be observed that the invention includes certain advantageous features involving the circulation and control of the drying medium in order that the drying operation may be effectively controlled.

While the invention has been described with reference to the specific forms illustrated in the drawings, it is not to be limited save as defined in the appended claims.

I claim:

1. Drying mechanism for use in drying sticky substances such as cooked riced potato and the like comprising a drying chamber, means to exert a drying action in the chamber, an endless conveyor in the chamber having upper and lower lengths and formed of a material having a specific heat suificiently low to cause the substance to adhere thereto during drying, spaced elements extending across the underside of the lower length of the conveyor to support said lower length in a manner preventing substantial injury to the substance on said underside, each of said elements comprising a plurality of coaxial, spaced apart, narrow, substantially circular elements engaging said lower length in substantially line 7 contact, means to introduce the said substance onto the upper side of the conveyor at one end thereof, and means to remove the substance from the underside of the conveyor at the said one end thereof.

2. Drying mechanism for use in drying sticky substances such as cooked riced potato and the like comprising a drying chamber, means to exert a drying action in the chamber, an endless conveyor in the chamber having upper and lower lengths and formed of a material having a specific heat sufiiciently low to cause the substance to adhere thereto during drying, means to support the lower length of the conveyor and including a rotatable member extending substantially across the underside of the lower length of the conveyor and formed of a plurality of coaxial, spaced apart, narrow, substantially circular elements and longitudinally extending substantially straight elements engaging said lower length in substantially lin contact to prevent substantial injury to the substance on the conveyor, means to introduce the said substance onto the upper side of the conveyor at one end thereof, and means to remove the substance from the underside of the conveyor at the said one end thereof.

3. Drying mechanism for use in drying sticky substances such as cooked riced potato and the like comprising a drying chamber, means to exert a drying action in the chamber, an endless conveyor in the chamber formed of a material having a specific heat sufliciently low to cause the substance to adhere thereto during drying, spaced elements extending across the underside of the lower length of the conveyor to support said lower length in a manner preventing substantial injury to the substance on the said underside, means at one end of the chamber to introduce the said substance onto the conveyor at one end thereof, means to remove the substance from the underside of the conveyor at the said one end thereof, discharge means at the opposite end of the chamber, and a second conveyor in the chamber beneath the first conveyor to receive substance removed therefrom and carry it to the discharge means.

4. Drying mechanism for use in drying sticky substances such as cooked riced potato and the like comprising a drying chamber, means to exert a drying action in the chamber, an endless conveyor in the chamber formed of a material having a specific heat sufii'ciently low to cause the substance to adhere thereto during drying, means at one end of the chamber to introduce the said substance onto the conveyor at one end thereof, stripping means to remove the substance from the underside of the conveyor at the said one end thereof, discharge means at the opposite end of the chamber, a second conveyor in the chamber beneath the first conveyor to receive substance removed therefrom and carry it to the discharge means, means to introduce a drying medium into the drying chamber, means to remove drying medium from the chamber between the conveyors and reintroduce it into the chamber above the first conveyor, and means to discharge the drying medium from the chamber.

5. Drying mechanism for use in drying sticky substances such as cooked riced potato and the like comprising a drying chamber, an endless conveyor in the chamber formed of a material having a specific heat suificiently low to cause the substance to adhere thereto during drying, means at one end of the chamber to introduce the said substance onto the conveyor at one end thereof, stripping means to remove the substance from the underside of the conveyor at the said one end thereof, discharge means at the opposite end of the chamber, a second conveyor in the chamber beneath the first conveyor to receive substance removed therefrom and carry it to the discharge means, means to introduce a drying medium into the chamber between the two conveyors, and means above the first conveyor and at the same end of the chamber as the last named means to discharge the drying medium from the chamber.

6. Drying mechanism for use in drying sticky substances such as cooked riced potato and the 4 like comprising a drying chamber, an endless conveyor in the chamber formed of a material having a specific heat sufiiciently low to cause the substance to adhere thereto during drying, means at one end of the chamber to introduce the said tsubstance onto the conveyor at one end thereof, stripping means to remove the substance from the underside of the conveyor at the said one end thereof, discharge means at the opposite end of the chamber, a second conveyor in the chamber beneath the first conveyor to receive substance removed therefrom and carry it to the discharge means, means to introduce a drying medium into the chamber between the two conveyors, means above the first conveyor and at the same end of the chamber as the last named means to discharge the drying medium from the chamber, and means to return predetermined portions of the discharged medium to the introducing means.

'7. Drying mechanism for use in drying sticky substances such as cooked rice potato and the like comprising a drying chamber, an endless conveyor in the chamber formed of a material having a specific heat sufficiently low to cause the substance to adhere thereto during drying, means at one end of the chamber to introduce the said substance onto the conveyor at one end thereof, stripping means to remove the substance from the underside of the conveyor at the said one end thereof, discharge means at the opposite end of the chamber, a second conveyor in the chamber beneath the first conveyor to receive substance removed therefrom and carry it to the discharge means, means to introduce a drying medium into the chamber between the lower and upper runs respectively of the said two conveyors, means to withdraw the drying medium from the chamber at the end thereof opposite the introducing means, means to heat the withdrawn medium and return it to the chamber at the last named end thereof and above the first conveyor, and means above the first conveyor and at the opposite end of the chamber as the last named means to discharge the drying medium from the chamber.

8. Drying mechanism for use in drying sticky substances such as cooked riced potato and the like comprising a drying chamber, an endless conveyor in the chamber formed of a material having a specific heat sufiiciently low to cause the substance to adhere thereto during drying, means at one end of the chamber to introduce the said substance onto the conveyor at one end thereof, stripping means to remove the substance from the underside of the conveyor at the said one end thereof, discharge means at the opposite end of the chamber, a second conveyor in the chamber beneath the first conveyor to receive substance removed therefrom and carry it to the discharge means, means to introduce a drying medium into the chamber between the lower and upper runs respectively of the said two conveyors, means to withdraw the drying medium from the chamber at the end thereof opposite the introducing means, means to heat the withdrawn medium and return it to the chamber at the last named end thereof and above the first conveyor, means above the first conveyor and at the opposite end of the chamber as the last named means to discharge the drying medium from the chamber, and means to return predetermined portions of the discharged medium to the introducing means.

ORVILLE GANO. 

